The present invention relates to a slide switch, and in particular to a slide switch such as a DIP switch which is suitable for being directly mounted to a printed circuit board for setting up data thereon.
Mounting a slide switch such as a DIP switch to a printed circuit board is typically done by performing automatic soldering. After completion of the automatic soldering process, it is usual for solder residues and so on to be adhered to the printed circuit board, and accordingly it is conventionally practiced to wash off such residues and the like by cleansing the printed circuit board in a cleansing liquid such as Freon.
However, during such a cleansing process, impurities are naturally carried off in the cleansing liquid, and there is a risk that the cleansing liquid may carry these impurities into a slide switch such as DIP switch fixed to the printed circuit board. Such impurities, if they settle on the contacts of the slide switch, can cause the contacting of the contacts to be deteriorated, and this can give rise to trouble during the use of the slide switch. Accordingly, there is a requirement for a sealing structure to be provided for such a slide switch for keeping cleansing fluid out of it during the cleansing process of the printed circuit board.
Now, one known type of such seal structure has the contacts of the slide switch tightly enclosed by a seal member, with a drive portion provided on the upper surface of this seal member so as to allow the contacts to be operated through the seal member. However, in the case of this construction, the problems arise that cleansing fluid is abstracted, because it can settle on and adhere to the seal member surface. Further, during the soldering process for fixing the slide switch to the printed circuit board, heat can be directly transferred to the seal member via the terminals of the slide switch and via its contacts, and this can risk deformation of or damage to the seal member. Further, in such a case, deformation of the movable contacts of the slide switch cold occur as a result of deformation of the seal member, and also the force required for operation of the slide switch is altered, as compared to the case in which the contacts of the switch are directly driven not through the seal member, which can unduly deteriorate the operability of the slide switch.
Further, there is another known method for preventing entry of cleansing fluid or contaminants into the slide switch, when a printed circuit board to which it is mounted is being cleansed, in which a separate member is provided for protecting the drive portion of the slide switch while the cleansing is being performed, since it is through this drive portion that the cleansing fluid tends to enter the switch. However, when such a separate member is used for preventing ingress of cleaning fluid, such a preliminary to the the cleansing process is troublesome, and further the requirement arises for removal of such a separate member from the printed circuit board and the slide switch mounted thereon after the cleansing process is completed, which causes further trouble. And because of this trouble the cleansing process becomes more costly.